ADCC in aging rats with methylcholanthrene-induced sarcoma (MC-Sa)

Investigations on the relationship between the aging of the immune system and the tumor growth are the trigger of our studies. The purpose of the present paper was to determine a relation between cytotoxic activity of the spleen lymphocytes in ADCC assay and the MC-induced sarcoma growth in adult and aging rats. In ADCC assay the mouse leukemia L1210 labeled with Cr and sensitized with rabbit anti-L1210 serum was used as target cells. In aging rats with MC-Sa tumors the lymphocyte activity in ADCC was increased or remained unchanged in the comparison with normal animals. On the contrary, in adult rats with MC-Sa tumors ADCC activity was decreased. In comparative studies between the groups of adult and aging rats a reverse relationship between the tumor growth and the lymphocyte activity in ADCC was found. In aging rats the level of ADCC was higher than in adults, but the tumor growth was slower. We suggest that ADCC phenomenon may be involved in an antitumor response, especially effective in aging rats.